CHAPTER 19 Focus Points
19.1 Coastal Processes: Tides, Waves, and Longshore Currents
Tides: Tides increase the vertical range of wave erosion in coastal areas.
Waves: Ocean waves are generated by wind. As they approach the shore, they slow down, grow higher, and break on the shoreline.
Sediment transport: Wave energy creates longshore currents that move sediments along a coastline.
19.2 Coastal Landforms: Beaches and Rocky Coasts
Emergent coasts: Most emergent coasts have erosional landforms such as steep cliffs and rocky shorelines.
Submergent coasts: Most submergent coasts have depositional landforms such as beaches and wetlands.
Coast types: Beaches and rocky coasts are two common coast types.
Beach landforms: Beach landforms include coastal sand dunes, baymouth bars, sandspits, tombolos, and barrier islands.
Sand loss from beaches: Artificial reservoirs trap sediment transported by streams and prevent it from reaching coastal beaches downstream, starving the beaches of sand.
Solutions to sand loss: Groins, seawalls, and beach nourishment are solutions used to address sand loss on beaches.
Erosion of rocky coasts: The force and weight of crashing waves break rock apart, forming various rocky landforms. These landforms include sea stacks and arches, headlands and embayments, wave-
19.3 Geographic Perspectives: The Sisyphus Stone of Beach Nourishment
Beach erosion: Beach erosion is a widespread problem that threatens coastal development and economies.
Beach nourishment: Beach nourishment is a common response to beach erosion, but it has many drawbacks.